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A '7 TOE/VEZ? S. D. DENKER SEWING MACHINE Aug. l2,` 1969 Filed Sept. 26, 1966 8 Sheets-Sheet 4 INVENTOR. Q
Filed Sept. 26. 1966 s. D. DENKER SEWING MACHINE 8 Sheets-Sheet 5 FIG. 8
Aug. l2, 1969 s. D. DENKER 3,460,494
SEWING MACHINE Filed Sept. 26, 1966 8 Sheets-Sheet 6 FIG. 6c
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SEWING MACHINE Filed sept. 2e, 196e 8 sheets-sheet'f/ FIG. 7o
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INVENTOR. 5274/1/55/ E f/KZ,
Aug. 12, 1969 s. DfDENKER 3,460,494
SEWING MACHINE Filed sept. 26. 196e s sheets-sheet B INVENTOR. 5274/1/55 MAM/2 United States Patent O 3,460,494 SEWING MACHINE Stanley D. Denker, New Richmond, Wis., assignor to Doughboy Industries, Inc., New Richmond, Wis., a corporation of Wisconsin Filed Sept. 26, 1966, Ser. No. 582,114 Int. Cl. D05b 13/00, 27/20 U.S. Cl. 112--11 11 Claims ABSTRACT F THE DISCLOSURE A sewing machine having a belt continuously moving the material being stitched, and having a developed cam moving the needle transversely of its normal reciprocation, and a cooperating l-ooper moving in the direction of movement of the material and cooperating with the transversely moving needle to effect stitching.
It has been conventional in industrial sewing machines to intermittently move the bag (this Word bag is used throughout the specification and claims to denote the sheet material, of whatever nature, being sewed) through the sewing head by gripping the material adjacent the needle and alternately holding the material in a stationary position and propelling the material to a new position. This intermittent movement severely limits the speed of operation of the sewing machine, and also is the cause of needle breakage and other instances of excess wear on the sewing head. It will be understood that even though the bag is intermittently moved at the sewing head, the other portions of the bag and the contents will conventionally be continuously traveling with and on a belt conveyor.
An object of my invention is to provide in a sewing machine, a new and improved mechanism of relatively simple and inexpensive construction and operation for stitching a continuously moving bag.
Another object of my invention is to provide in a sewing machine, an improved needle operating and thread manipulating mechanism whereby a continuous movement of the -bag is accommodated and wherein the needle, while in the bag during stitching is moved uniformly with the bag and in the direction of bag movement.
Still another object of my invention is the provision in a sewing machine producing a double locked chain stitch for closing the top of a bag, of a new and novel mechanism controlling the thread.
These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like character references refer to the same or similar parts throughout the several views, and in which:
FIG. 1 is a perspective view of the invention;
FIG. 2 is a front elevation view of the invention with the front cover removed and with certain portions broken away and shown in section for clarity of detail;
FIG. 3 is an enlarged detail section view taken approximately at 3-3 in FIG. 2;
FIG. 4 is an enlarged detail section View taken approximately at 4-4 in FIG. 2;
FIG. 5 is an enlarged detail section view taken approximately at 5 5 in FIG. 2;
FIGS. 6a, 6b, 6c and 6d are greatly enlarged detail section views showing the needle and looper substantially in the manner of FIG. 4 and successively illustrating the relative positions of the needle and looper at various steps of an operational cycle, and specifically at 0, 90, 180 and 270 respectively, of the operating cycle;
FIGS. 7a, 7b, 7c and 7d are greatly enlarged detail views taken approximately at 7-7 of FIG. 4 and illustratrice ing. the relative positions of the needle and looper at various steps of an operational cycle, and specifically illustrating the relative positions at 0, 90, 180 and 270 respectively of an operational cycle;
FIG. 8 is an enlarged detail section view taken approxrmately at 8--8 in FIG. 2;
FIG. 9 is a greatly enlarged detail section view of a portion of the mechanism as indicated at 9--9 in FIG. 4;
FIG. l0 is a bottom plan view of the machine with portions thereof broken away for clarity of detail at 10-10 in FIG. 2.
One form of the invention is shown in the drawings and is described herein.
The sewing machine is indicated in general by numeral 15 and includes a frame structure which, as illustrated, constitutes a casting so as to mount all of the bearings and operating parts in predetermined relation with each other. The casting 16 comprises a housing for the operating mechanism of the machine and which carries a rigid cover 17 thereon when the machine is in operating condition. The cover 17 is held to the casting or housing 16 by a thumb screw 17a which, when removed, permits the entire cover and lboth threads 18 and 19 to be moved out of the way so that the interior of the machine may be serviced, such as for lubricating. A second cover 20 covers a portion of the housing or casting 16 and when removed, exposes the looper control mechanism, indicated in general by numeral 21 and the looper thread guides. The cover 20 carries a pair of permanent magnets 20a thereon which, when the cover is in place, confront magnetic pads 16a of the housing. The cover 20 may be readily and easily removed without disturbing any of the threading of the sewing machine by simply nudging the forwardly projecting 20h thereof.
It will be understood that the threads 18 and 19 are supplied to the sewing machine from spools 18a and 19a respectively, which are supported by a suitable bracket structure 22 which is suitably aixed to the casting 16. A stationary thread guiding xture 23 is also aixed to the casting 16 and defines thread guiding eyelets or apertures 23a, 2311 and 23e` in order to direct the needle and looper threads 18 and 19 to the guideways 24 and 25 on the front face of the cover plate 17.
It will be noted that the thread guideway 24 has a pair of guide blocks 24a and 24b affixed to the cover 17 and apertured to receive the needle thread 18 therethrough and to guide thread 18 into the thread tensioning device 24C which adjustably tensions the thread, according to the setting of the lock nuts 24d. An additional thread guiding block 24e directs the thread from the tensioning device to the sewing head.
The thread guideway 25 includes a thread guiding block 25a and a thread tensioning device 25h which applies tension to the looper thread to the desired degree, depending upon the setting of the lock nuts 25e. Ordinarily, the looper thread 19 will have only a minimum of tension applied.
The sewing machine is connected to a source of rotary power, such as V-belt 26 which transmits power from an electric motor which operates at a speed so as to revolve the power receiving pulley 27 on the casting 16 at a speed of approximately 1725 r.p.m.s to 2200 r.p.m.
It has been found that the sewing machine operates satisfactorily at these speed ranges. The power transmitting mechanism in the sewing machine transmits the rotary motion to the looper assembly 21 and to the sewing head 30 at a l to l speed ratio so that the machine has the same rate of operation as the power supplied thereon.
Rotary power is transmitted from the pulley 27 to the input drive shaft 27a and then by gearing 28 to the counter shaft 28a which drives a unitary drive roller and sprocket 29 at a rate such that the periphery of the roller 29 has a linear rate of travel of approximately 50G-650 inches per minute.
It should be understood that the shaft 28a and roller 29 operate continuously for the purpose of continuously moving the bag or fabric or sheet material B through the sewing head 30 at a substantially constant rate. The roller 29 has three distinct side by side areas on its periphery, the central area 29a is knurled, and the other outermost peripheral areas are toothed at 29b so as to receive and drive, in the manner of a sprocket. The central knurled portion of 29a of roller 29 is disposed opposite a movable clamping roller 32 in an arrangement such that the bag B will pass between the rollers 29 and 32 and be tightly gripped and driven by the knurled surface of portion 29a of roller 29. The periphery of roller 32 is preferably also knurled. Roller 32 is journalled on a movable mounting block 33 aixed as by set screw 33a to a mounting rod 33b which is guided for sliding movement in a bearing aperture 34a of a bearing block 34 which is affixed to the frame or cas-ting 16 as seen in FIG. 5.
The mounting rod 33b has a rigid collar 33C atlixed thereon; and a coil compression spring 33a' bears against the collar 33C and also bears against a stationary bearing block 35 afxed to the frame 16 and slidably receiving the mounting rod 33b therethrough. The' spring 33d applies pressure through the rod 3319 so as to continuously urge the roller 32 against the roller 29 and thereby tightly clamp the bag B therebetween.
The belts 31a and 31b are also trained around roller 36 which is also toothed at its periphery to mount and guide the belts. The belts 31a and 3117 are also guided around a stationary slide bearing 37 adjustably mounted, by means of a stud 37a to the frame or casting 16.
The roller 36 is mounted by means of a hub 36a in a slot 16a` of the frame or casting 16 so as to be adjustable to a desired degree.
The relative relationship between rollers 29 and 36 directs the belts 31a and 31b 4through the sewing head 30 for carrying the bag B therethrough, in cooperation with the bag clamping and driving rollers 29 and 32. It will be noted that bag conveying runs of the belts are directed over a rigid back-up plate 38 afxed to the frame or casting 16. The plate 38 has an elongate slot 38a therein and also has belt receiving grooves 38b which prevent any sideward movement of the belts. The linear rate of travel of the periphery of roller 29 produces a substantially identical linear rate of travel of the belts 31a and 31b against which the bag B lies and is transported during sewing. It has been found that the desired continuous travel of the bag B can be obtained by eliminating the conveyor belts 31a and 31b and applying rotary driving power to the upper roller 32 which confronts the drive roller 29 at a rotary speed coordinated with that of the roller 29.
It will be noted that means is provided for clamping the bag B against the belts as they carry the bag through the sewing head, and in the form illustrated, the clamping is accomplished by a rigid elongate plate or foot 39 axed on the bearing block 33 and movable therewith toward and away from the belts 31a and 31b. The forward portion 39a of the foot 39h is inclined so as to quickly guide' the leading edge of the bag B into the space between the belt and the foot. The foot 39 also has an elongate slot 39b which is disposed vertically above and in alignment with the slot 38a on the back-up plate 38.
The sewing head 30 also receives its operating power from the input drive shaft 27a upon which a pulley 40 is mounted. A drive belt 49a and a power receiving pulley 40b is ati'ixed to a jack shaft 41, the opposite ends of which are journalled in suitable bearings on the casting or frame 16. The belt 40a is preferably toothed at its inner side and the pulleys 40 and 40b are also toothed at their periphery and their sprockets for maintaining the desired rate of power transmission between shaft 27a and shaft 41. A tensioning idler pulley 40e is also adjustably mounted on the frame in mesh with toothed drive belt 46a.
Shaft 41 has a crank arm 41b ailixed on its end and rotatably connected to a reciprocable driving link 42. The other end 42a of the link is connected for rocking motion to a pivot pin 43 on a driving collar 43a which is aflixed to the needle bar 44. The needle bar 44 has the sewing needle 45 affixed on its inner end by a conventional needle-mounting tting 44a. The needle bar effects reciprocation of the needle in a direction longitudinally thereof and also effects transverse movement of the needle 45 in the direction of bag movement as indicated in FIG. 4 by arrow A.
It will be seen that the needle 45 is provided with grooves 45a at its opposite fore and aft sides and is provided with a thread receiving aperture 45h adjacent its pointed end.
The needle bar 44 has its outer end portion mounted in a bearing 44b for sliding and limited rocking or oscillatory movement in a direction transversely of the nee'dle.
The inner end portion of the needle bar 44 is slidably mounted in a slide bearing 46a which is mounted in a bearing block 46 for limited rocking or swinging movement. The bearing block 46 reciprocates linearly, first in the direction of arrow A and then in the exact opposite direction so as to produce travel of the needle 45 in the direction transversely thereof.
Bearing block 46 is mounted on an elongate slide 46a guided in and coniined by the slide block 34. The slide 46a has a reduced end portion 46b and a shoulder 46c against which the end of compression spring 47 lies. The spring 47 is disposed within a recess 34b of the bearing block 34, and the other end of the compression spring bears against an adjustable anchor or mount 48a on a threaded stud 48b which is threadably mounted in a mounting block 48 affixed on the frame 16. It will be seen in FIG. 5 that the bearing block 46 is movable from the full line position to the dotted line illustrated for producing the transverse movement of the needle 45.
The movement of the bearing block 46 and the needle bar 44 is effected from a developed cam 49 which is axed on the shaft 41 adjacent the crank arm 41b. The developed cam 49 continuously revolves with the shaft 41, and a cam follower 50 continuously bears against the peripheral surface of the cam 49 so as to oscillate under the influence of the cam. The cam follower 50 is mounted on a pivot 51 which is affixed to the frame or casting 16, and the opposite end of the cam follower carries a control rod 50a which is slidably mounted in a tiltable bearing 46e and carried by the bearing block 46. It will be seen that as the cam 49 revolves, the follower 50 rocks about the pivot 51 so as to produce linear movement of the bearing block 46, thereby producing movement of the needle in a direction transversely thereof. It is to be particularly noted that from the time the needle 45 moves into the fabric of the bag B, the needle will remain inserted into the material of the bag for approximately 240 of the operational cycle of the sewing machine, after which the needle is removed from the bag. All during this period of each operational cycle when the needle is inserted into the fabric of the bag, the needle 45 moves transversely in the direction of arrow A, which is the direction of the bag movement, and at a rate substantially identical to the constant rate of travel of the bag B, so that there is essentially no relative movement betwen the needle 45 and the bag B in a direction transversely of the needle 45. The sliding movement of the needle bar 44 produced by the crank arm 4119 produces the conventional reciprocating stroke of the needle 45 into and through and out of the bag so as to carry the thread rnto and through the bag B in producing the double lock chain stitch, in cooperation with the looper assembly and the thread 19 supplied thereto.
The looper assembly 21 includes the looper 52 which is moved with an cndwise sliding movement, and a fore and aft rocking movement so as to first move longitudinally across the front side of the needle 45, and then longitudinally across the rear Of the needle 45 in a motion which is typical of sewing machines producing the double lock chain stitch which is commonly -used for stitching bags, wherein the stitching is to be reopened. The looper 52 is provided with a longitudinal groove 52a at one face thereof in which the thread will normally lie, and a thread carrying aperture 52b.
The looper 52 is aixed to a rocker arm 53 which is atlixed to a rocker shaft 53a mounted for sliding and rocking movement in bearing apertures 54 in the frame or casting. The rocking motion of the shaft 53a and of the arm 52 is produced by a rigid yoke 55 aixed on the rocker shaft 53a, and having a pair of depending cam follower arms 55a and 55h which confront each other and which carry wear plates 55e as of bronze or oilite material. The cam following arms engage opposite sides of a cylindrical rotary eccentric or crank 56 which is mounted on and driven by the input drive shaft 27a. It will be seen in FIG. 8 that as the shaft 27a is revolved, the yoke 55 will rock from side to side under the influence of the eccentric 56 and thereby produce a rocking motion of the shaft 53. It will be noted that in FIG. 2 the eccentric is of an elongate cylindrical shape as to accommodate movement of the yoke 55 in a direction endwise of the shaft 27a and eccentric 56. The endwise motion of the yoke 55 is indicated by the dotted line position of the yoke 55 which corresponds in magnitude to the endwise movement of the looper 52 and rock shaft 53a.
The endwise movement of the rock shaft is produced by a cylindrical eccentric 57 atxed on the drive shaft 27a and captured in a holder 57a which moves transversely of the shaft 27a as the shaft and cam 57 are revolved. Endwise movement of the connecting rod 58 is produced, and a crank arm 59, which is ai'lixed at pin 60 to the frame or casting 16 is connected to the link 58 by a universal joint or bearing 59a. The opposite end of the arm 59 is connected by a universal bearing 59h to the end of rock shaft 53a so as to produce endwise motion of the looper in coordinated relation with the rocking motion thereof.
The coordinated movement of the needle and the looper is illustrated in FIGS. Gaz-6d and 7a-7d, and although these relationships are illustrated without thread being illustrated in the needle and looper, the action of these parts will be understood by a person of skill in the art in view of the similarity to other needle and looper relationships wherein the double lock chain stitch is produced. For purposes of this description, the start of the cycle of operation (0) is assumed to be the position substantially as illustrated in FIGS. 3 and 4, wherein the needle has reached its point of maximum withdrawal from the bag, and the crank arm 4111 is in a position such that the connecting link 42 is parallel with the needle bar 44.
Especially with respect to the needle 45, and its motion, in FIG. 6a the needle is seen to be moving downwardly and forwardly in a direction opposite to the direction of the bag movement as indicated by arrow A in a substantially curved path of movement, as indicated in arrow N. In FIG. 6b, the needle 45 is still moving downwardly, but in this instance is moving in the direction of arrow A and at a rate identical to the rate of travel of the bag B, such that the needle is moving obliquely downwardly in a curved path, substantially as indicated by the arrow O in FIG. 6b. At 180 of the operational cycle, the needle 45 has been inserted through the bag to its maximum extent, and at this instance, the needle has essentially no Vertical component of movement, but soon after the exact instant illustrated in FIG. 6c, the needle will start withdrawing from the bag B. In FIG. 6c, the needle is moving substantially entirely in a transverse direction, almost identically to the direction of arrow A, but in a slightly curved path of movement, substantially as indicated by arrow P.
Subsequently, as the needle 45 is being withdrawn from the bag B, the needle 45 is still being moved transversely of its length, substantially in the direction of arrow A so that the resultant direction of movement of the needle 45 at this instant is along a curved path, substantially in the direction of arrow Q as illustrated in FIG. 6d.
It will be understood that the motion of the needle 45 is extremely rapid, and may be 1725 to 2200 cycles per minute.
After the needle 45 has withdrawn from the bag B, it commences to travel in the direction opposite to arrow A as the needle continues to rise upwardly towards the 0 position illustrated in FIG. 6a so that the needle is preparing with respect to the fabric of bag B to be inserted again at a new location. The extremes of the transverse movement of the needle are approximated in FIGS. 6b and 6d, and in FIG. 4 the relative position of the needle as it is about to enter the bag B, and as it has just left the bag B is respectively illustrated in dotted lines and indicated by numerals 45 and 45".
The fore and aft movement of the needle 45 is not visible as viewed in FIGS. 7a-7al, but the motion of the looper 52 can be clearly observed.
As the needle 45 descends in FIG. 7a, the looper 52 is withdrawing to the position illustrated in FIG. 7c where the looper rocks rearwardly so that it is subsequently projected along the rear side of the needle, substantially as illustrated in FIGS. 7d and 6d. When the needle has withdrawn from the bag, the looper 52 is again rocked forwardly to the front of the needle, in a manner well known to persons familiar with sewing machines producing the double lock chain stitch.
It will be understood that the extreme positions of the looper 52 are not necessarily illustrated in FIGS. 7a-7d because these figures are primarily for the purpose of illustrating the relative motions.
The -sewing machine is provided with a means for sensing the presence of a bag which has been moved into the vicinity of the sewing machine as by a belt conveyor C, and such means includes a movable bag sensing bar 61 adjacent the foot 39 and mounted on swingable arms 61a and 62, both of which is mounted on pivots 63 so as to be swingable on the frame or casting 16. The arm 62 has a return spring 62a connected thereto and also anchored to a bracket 62h on the frame or casting 16. The arm 62 confronts the operating element 63 of a micro-switch 63a which is connected to the motor supplying rotary driving power to the belt 26 and pulley 27. It will be understood that a bag, when moving along the belts 31a and 31b and in engagement with the foot 39, will deflect the sensing bar 61 to operate the switch for thereby starting the sewing machine. Stitching of the bar commences as soon as the bag passes under the needle.
The sewing machine is also provided with means for cutting olf the chain of stitching produced after the trailing edge of the bag B has passed beneath the needle 45. Such severing means includes a rigid guide block 64 affixed as by screws 64a to the frame or casting 16 of the machine. The block 64 has a bag guiding face 64b disposed in obstructing, deflecting and oblique relation with the normal path of bag movement as the bags are delivered between the rollers 29 and 32 so lthat the bag B will have its course or direction changed slightly and will pass along the surface 64b. As particularly seen in FIG. 10, the guide block 64 has its edged portion 64C in closely spaced relation with the outer surface of the belts 31a and 31b so as to assure that the bag B will pass over the surface 64b. A iiat leaf spring 65 is disposed in confronting relation with the belts 31a and 31b and roller 29 and has its edge normally biased against the guide surface 64b such that the spring will be deflected away from the guide block 64 when the bag B is carried along its normal course. The spring 65 has a slot 65a formed therein which normally receives the roller 32 therein and the spring 65 is disposed on both sides of the roller 32 for maximum engagement with the bag B. A supplemental guide 66 is provided on the frame or casting 16 so as to form a continuation of the top guiding surface 64b of the block 64.
The guide block 64 has a recess or notch 67 formed in the upper portion thereof and in alignment with the roller 32 and the central knurled portion 29a of roller 29, so that the recess 67 is also disposed in alignment with the needle 45 whereby the stitching S in the bag B as seen in FIG. 9 will pass over the notch 67. Similarly, after the trailing edge of the bag B has passed over the guide block 64, the chain of stitched thread S will actually pass through the notch 67 and will be forced downwardly thereinto by the leaf spring 65, which after the bag passes from beneath the spring 65 will bear downwardly against the surface 64b of the guide block 64, so as to capture the chain of stitched thread S' in the notch 67.
One of the upright side edges 68 of the notch 67 comprises a sharpened stationary edge for cooperation with the cutter 69 for severing the chain of stitched thread S in the notch 67. The cutter 69 has a sharpened edge 70 sufcient in length to extend to the upper terminal end of the edge 68. The end portion 69a of the cutter 69, and beyond the cutting edge 70 is smoothly rounded so as to normally pass beneath the bag B and gently move the bag B away from the surface 64b each time the cutter 69 swings across. The stitching S in the bag is uplifted with the bag B and the cutting edge 70 has no effect whatever on the stitching in the bag. The cutter is moved across the notch 67 and in shearing relationship with the anvil edge 68 in each operational cycle of the sewing machine, such that as soon as the chain of stitched thread 70 drops into the notch 67 it will be immediately severed, closely adjacent the side edge of the bag B. The cutter 69 is operated by a connecting length 69d which is pivoted to a crank arm 59d so as to be operated by the crank arm 59 from the eccentric 57.
The cutter 69 is swingably mounted on the guide block 64 as by pivot 70.
In operation, it is to be particularly noted, that during each operational cycle of the sewing machine, the needle is inserted into the bag and remains in the bag for approximately 240 of the operation-al cycle. All during this period, the needle travels transversely of its length, and in the direction that the bag is being continuous-ly moved under influence of the rollerss 29 and 32 and the belts 31a and 31h. As a result of the transverse movement of the needle at a rate substanti-ally identical to that of the continuously moving bag, the transverse strains and stresses on the needle 45 are minimized, and the sewing machine is operated fast, but with minimum needle breakage and other wear on the operating parts. The needle and needle bar 44 are lmoved with a slight swinging action about the center approximately at bearing 44h which is disposed above the crank arm 41h. The needle and needle -bar swing, from the centerline position of the needle, rst `forwardly to the position 45 illustrated in dotted lines in FIG. 4 to an angle of approximately 11/2 to 2 degrees, =at which time the needle enters the bag. While the needle is in the bag, the needle and needle bar swing rearwardly, moving in the direction of arrow A of the bag and towards the dotted line position of the guide block as illustrated in FIG. until the needle and needle bar have swung through an angle of approximately 11/2 to 2 degrees from the centerline position of the orbital movement of the needle and needle bar, at which time the needle is withdrawn from the bag and moves back toward and through its normal centerline position again.
In one embodiment of the invention, stitching is produced in the bag at a rate of 3.45 stitches per lineal inch along the bag. Stitching at a rate of 500 to 650 inches per minute has been easily accomplished at operational rates of 1725 to 2200 cycles per minute.
It will be recognized that as a result of the needle being in the bag for substantially 240 of the operational cycle, the lineal endwise movement of the needle bar 44 and the needle 45 is minimized, and in a similar manner the lineal movement of the looper 52 and the corresponding endwise movement of the rocker shaft 53a is minimized.
The sewing of the bag while the bag is continuously moving is obviously advantageous in view of the fact that most of the bag supporting and carrying conveyors C as illustrated in FIG. 1 are continuously moving in operation and by allowing the -top of the bag B to also continuously move through the sewing machine minimizes likelihood of undue stresses being applied to the sewing mechanism.
It will be understood that the front cover 17 may be readily removed without unthreading the entire machine, and when the cover 17 is replaced after servicing the interior mechanisms, the thread 18 need merely be slipped through the line guiding eyelet 4411 axed on the needle bar 44, and through the cover -aperture 17a and directly to the needle as illustrated. The looper thread 19 needs merely to be inserted through the line guiding yaperture 53a in the looper arm and then through the aperture 52b in the looper.
It will be seen that I have provided a new and improved sewing mechanism wherein the bag being sewed is moved continuously at a constant rate through sewing mechanism and the sewing of the bag is accomplished while the bag is continuously moving. The needle is moved transversely of its longitudinal direction while the needle is inserted in the bag and at a rate which is substantially equal to that of the bag. The needle is maintained in the bag for approximately 240 of the operational cycle so as to minimize the necessary longitudinal movement of the needle in its operational cycle. The transverse movement of the needle is produced by a developed cam so that the needle may remain in the bag throughout most of the operational cycle and then quickly return to form a new stitch as the needle is reinserted into the bag.
It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departnig from the scope of my invention.
What I claim is:
=1. A sewing machine for stitching a bag, comprising a frame, a source of rotary power with power delivery means journalled on the frame, and a sewing head receiving rotary power and having propelling means engaging the bag adjacent the area to be stitched and continuously moving the bag through the sewing head, said sewing head including a needle bar with a thread carrying needle on the inner end thereof, the needle being reciprocated through the bag,
means producing transverse movement of the needle in the direction of movement of the bag and including a cam effecting said transverse movement of the needle uniformly with the movement of the bag while the needle extends into the bag,
and a thread carrying looper in the sewing head and cooperating with the needle reciprocating through the bag to eect stitching of the bag.
2. The sewing Imachine according to claim 1 wherein said sewing head cyclically reciprocates the needle into and out of the bag, the needle extending into the bag for a period well in excess of 180 of the cycle of operation, said cam effecting uniform transverse movement of the needle with the bag while the needle extends into the bag.
3. The sewing machine according to claim 1 wherein said sewing head cyclically reciprocates said needle into and out of the bag, said needle extending into the bag during a period of substantially 240 of the cycle of operation, and said cam effecting substantially uniform transverse movement of the needle with the bag and only in the direction of lthe bag all during said 240 of the cycle.
4. The sewing machine according to claim 1 and including bearing `means mounting the outer end of said needle bar for longitudinal reciprocation and for swinging oscillation, and a slide guiding the inner end of the needle bar with the needle thereon in said transverse movement with the bag while the needle extends in-to the bag.
5. The sewing machine according to claim `4 and including a rotary crank producing reciprocation of the needle bar and needle, said calm being connected with the crank and revolving therewith, and a rocking cam follower pivoted to the frame land connected to said slide land producing said uniform transverse movement of the needle with the bag.
6. The sewing machine according to claim 4 wherein the needle bar and needle swingably oscillate through an intermediate position normal to the direction of bag movement, the swinging of the needle bar and needle being limited to an angle of approximately one and onehalf to two degrees of said intermediate position.
7. A sewing machine for stitching a bag,
comprising a frame, a source of rotary power with power delivery means journalled on the frame,
a sewing head receiving said rotary power and having a stitching station and also having a propelling station continuously drawing the bag from and through the stitching station,
a needle bar at the stitching station and having a thread carrying needle on the inner end thereof and being reciprocated through the bag,
means producing transverse movement of the needle in the direction of continuous movement of the bag while the needle extends into the bag,
a thread carrying looper -at the stitching station and cooperating with the needle to effect stitching of the bas,
and said propelling station being spaced in the direction of bag movement from the stitching station and including a pair of continuously revolving bag clamping and driving rollers aligned with the needle Iand also clamping and driving the thread of the stitching whereby to continuously draw the bag through the stitching station and also to continue to draw the chain of stitched thread from the reciprocating needle and looper after completion of stitching of the bag.
8. The sewing machine according to claim 7 and said sewing head also including a continuous bag delivery belt extending along the stitching station and drivably connected with said rollers to carry the bag to the needle after which the bag is drawn through the sewing head by the chain of stitched thread and rollers.
9. A sewing machine for stitching a bag,
comprising a frame defining a housing having an open front, a source of rotary power with power delivery means on the frame,
a sewing head on the -frame within the housing and dening a path of bag movement, said head including a looper assembly on one side of the p-ath of bag movement and also including, at the other side, a needle and needle bar with a moving thread guide attached thereto,
and -a removable front cover with a pair of thread guideways for the needle and looper threads respectively, said guideways including tensioning and guiding means maintaining the threads in predetermined relation while the cover .is in place on the housing during sewing operation and while the front cover is removed for servicing the sewing head whereby to facilitate ready and easy re-threading of the needle and looper assembly.
10. A sewing machine for stitching a bag,
comprising a frame, a source of rotary power with power delivery means journalled on the 4frame and a sewing head receiving rotary power yand having propelling means engaging in moving the -bag through the sewing head and directing the chain of stitched thread along `a predetermined path of movement after the trailing edge of the bag has been stitched, a stationary guide member at the delivery end of said propelling means to receive the stitched bag therefrom, the guide member having a notch therein and aligned with the sewing head to receive the stitched chain of thread as the bag passes along the guide mem-ber and therebeyond, said guide member defining a sharpened edge at one side of said notch,
a pressure plate confronting said guide member and urged toward the guide -member under spring pressure to urge the bag against the guide member being propelled from the sewing head, said pressure plate overlying said notch and guiding the chain of stitched thread into the notch after the trailing edge of the bag passes beyond said guide member, `a swingable cutting blade pivotally mounted on said guide member and extending generally toward said pressure plate to swing `across said notch and sharpened edge, one end of said blade extending into` close proximity with said pressure plate to engage any of the chain of thread in said notch, and being smoothly rounded to move smoothly past a bag being guided over said guide member without interferrng with the thread stitched thereto, said blade being connected with the source of rotary power to be periodically operated in coordinated relation with the sewing head.
11. The sewing machine according to claim 3 and including an eccentric oscillating said looper inthe direction of movement of the bag and producing cyclic operation thereof in cooperation with the needle,
a rotary crank producing reciprocation of the needle bar and needle,
all of said eccentric means, rotary crank, and cam being driven from a single source of rotary power and coordinated in their respective motions.
References Cited UNITED STATES PATENTS 804,220 11/1905 Gray 112-213 1,450,456 4/ 1923 Seymour 112--213 2,035,848 3/1936 Thompson 112-11 2,151,438 3/1939 Pierce 112-11 X 2,171,130 8/1939 Merrifield 112-11 2,203,580 6/ 1940 Ronning.
2,411,459 11/1946 Perkins et al 112-258 2,476,752 7/ 1949 McLaughlin 112-203 2,546,527 3/1951 Smyth 112--203 2,749,861 y6/ 1956 Quist 112--213 3,046,919 7/1962 Fox 112-11 3,082,718 3/ 1963 Scharmer 112-11 3,213,814 10/1965 Boser 112-203 X ALFRED R. GUEST, Primary Examiner U.S. Cil. XR. 112.-203, 213